B1552
Title: Functional data analysis of three-dimensional surface data: Examples on human face
Authors: Stanislav Katina - Masaryk Univesity (Czech Republic) [presenting]
Abstract: The advent of high-resolution imaging has made data on surface shape widespread. Methods for the analysis of shape based on landmarks are well established, but high-resolution data require a functional approach. The starting point is a systematic and consistent description of each surface shape (using, e.g., curves, and surface patches) and a method for creating this is described. Two innovative forms of analysis are introduced. The first uses surface integration to address issues of registration, principal component (PC) analysis, all in functional form. Computational issues are handled through discrete approximations to integrals based on appropriate surface area weighted sums. The second innovation is to focus on subspaces where interesting behaviour such as group differences are exhibited, rather than on individual PCs. All these ideas are developed and illustrated in the important context of the human facial shape of patients before and after orthognathic surgery and patients with psychotic or other disorders and controls, with a strong emphasis on effective visual communication of effects of interest. All presented methods are implemented in R as part of a face3d package development.
